include(${CMAKE_ROOT}/Modules/CMakeDependentOption.cmake)
option(USE_CURL "use libcurl" ON)
option(USE_MATH "use libm" ON)
cmake_dependent_option(DEPENT_USE_CURL "this is dependent on USE_CURL" ON "USE_CURL AND NOT USE_MATH" OFF)
if(DEPENT_USE_CURL)
    message(STATUS "using lib curl")
else()
    message(STATUS "not using lib curl")
endif()
 